Transmisson diversity system

• US 5,809,019 A
• Filed: 04/25/1996
• Issued: 09/15/1998
• Est. Priority Date: 04/28/1995
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ichihara, Masaki, Furuya, Yukitsuna
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US08/637,499
• Time in Patent Office: 873 Days
• Field of Search: 370/252, 370/334, 370/491, 375/267, 375/347, 455/101
• US Class Current: 370/334
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/364 Delay profiles
• CPC Class Codes: H04B 7/061 using feedback from receiving side
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001

Abstract

In a transmission diversity system for selecting one of a plurality of radio transmission systems in a base station to perform diversity transmission of data to a mobile station, the base station adds transmission data and identification signals different in the plurality of radio transmission systems to transmit resultant radio signals from the plurality of radio transmission systems, and transmits transmission data from one radio transmission system based on optimal radio transmission system information transmitted as a radio wave from the mobile station. The mobile station determines an identification signal representing an optimal reception state from the plurality of identification signals detected from the data received from the plurality of radio transmission systems of the base station and transmits the determined optimal radio transmission system information to the base station.

Claims

1. A transmission diversity system for selecting one of a plurality of radio transmission systems in a base station to perform diversity transmission of data to a mobile station,

wherein said base station adds transmission data and identification signals different in the plurality of radio transmission systems to transmit resultant radio signals from said plurality of radio transmission systems, and transmits transmission data from one radio transmission system based on optimal radio transmission system information transmitted as a radio wave from said mobile station, and

said mobile station determines an identification signal representing an optimal reception state from the plurality of identification signals detected from the data received from the plurality of radio transmission systems of said base station and transmits the determined optimal radio transmission system information to said base station.

2. A system according to claim 1, wherein

said base station comprises

identification signal generation means for generating the plurality of types of identification signals different in the plurality of radio transmission systems,

setting means for setting transmission or non-transmission of data respectively constituting said plurality of radio transmission systems,

addition means for adding the identification signals from said identification signal generation means and the data output from said setting means and outputting resultant addition data,

base station radio transmitting means for transmitting the radio addition data respectively output from said addition means,

base station radio reception/extraction means for receiving radio transmission from said mobile station and extracting the optimal radio transmission system information representing transmission through an optimal radio transmission system determined by said mobile station, and

selection means for setting non-transmission of data from said setting means except for one radio transmission system based on the optimal radio transmission system information extracted by said base station radio reception/extraction means;

and

said mobile station comprises

mobile station radio reception means for outputting data received from said base station,

identification signal detection means for detecting the plurality of identification signals different in said plurality of radio transmission systems from data received by said mobile station radio reception means,

determination means for determining one of the plurality of identification signals detected by said identification signal detection means, and

mobile station radio transmission means for transmitting the optimal radio transmission system information representing a radio transmission system of said base station which transmits the identification signal determined by said determination means.

3. A system according to claim 1, wherein

said base station comprises

identification signal generation means for generating one identification signal,

delay means for delaying the identification signal from said identification signal generation means;

setting means for setting transmission or non-transmission of data respectively constituting a plurality of radio transmission systems,

addition means for adding data output from said setting means and the identification signal from said identification signal generation means or said delay means and outputting resultant addition data,

base station radio transmission means for transmitting the radio addition data respectively output from said addition means;

base station radio reception/extraction means for receiving radio transmission from said mobile station and extracting optimal radio transmission system information representing transmission through an optimal radio transmission system determined by said mobile station, and

selection means for setting non-transmission of transmission data from said setting means except for one radio transmission system based on the optimal radio transmission system information extracted by said base station radio reception/extraction means; and

said mobile station comprises

mobile station radio reception means for outputting data received from said base station,

identification signal detection means for detecting the plurality of identification signals of said plurality of radio transmission systems from the data received from said mobile station radio reception means,

determination means for determining one of the plurality of identification signals which is detected by said identification signal detection means and represents an optimal reception state, and

mobile station radio transmission means for transmitting the optimal radio transmission system information representing a radio transmission system of said base station which transmits the identification signal determined by said determination means.

4. A system according to claim 3, wherein said identification signal detection means comprises:

identification signal search means for calculating a sliding function between a reception signal and the identification signal serving as a reference from said identification signal generation means and obtaining a delay profile representing field strengths of the identification signals with respect to a delay time; and

determination means for obtaining the optimal radio transmission system information representing one of the plurality of identification signals which has a highest signal strength from the delay profile obtained by said identification signal search means.

5. A system according to claim 2, wherein said setting means comprises a plurality of variable attenuation means for variably attenuating the transmission data for the respective radio transmission systems and setting the transmission data in an output or non-output mode.

6. A system according to claim 2, wherein said setting means comprises switches for setting transmission or non-transmission of the transmission data for the respective radio transmission systems.

7. A system according to claim 2, further comprising encoding means for encoding a plurality of transmission data for a plurality of mobile stations and outputting encoded data to said setting means.

8. A system according to claim 7, wherein said encoding means employs a CDMA (Code Division Multiple Access) scheme as a multiplexing scheme.

9. A system according to claim 3, wherein said setting means comprises a plurality of variable attenuation means for variably attenuating the transmission data for the respective radio transmission systems and setting the transmission data in an output or non-output mode.

10. A system according to claim 3, wherein said setting means comprises switches for setting transmission or non-transmission of the transmission data for the respective radio transmission systems.

11. A system according to claim 3, further comprising encoding means for encoding a plurality of transmission data for a plurality of mobile stations and outputting encoded data to said setting means.

12. A system according to claim 11, wherein said encoding means employs a CDMA (Code Division Multiple Access) scheme as a multiplexing scheme.